package ch04.d1;

public class Person{
    String name;
    int age;
    public Person(){
        System.out.println("父类无参构造器");
    }

    public Person(String name){
        System.out.println("父类有参构造器");
    }
    public void sing() {
        System.out.println("唱歌");
    }

}
